scholarly journals Effect of Pouring Temperature and Heating of Ceramic Shells Mould on Projection of Thin Wall Castings

2021 ◽  
Vol 60 (2) ◽  
pp. 81-89
Author(s):  
Zdzisław Żółkiewicz ◽  
Łukasz Rogal ◽  
Wojciech Maj ◽  
Wojciech Maziarz ◽  
Piotr Tkaczewski ◽  
...  
Keyword(s):  
Cast Steel ◽  
Research Work ◽  
Iron Alloy ◽  
Iron Alloys ◽  
Thin Wall ◽  
Ceramic Shell ◽  
Pouring Temperature ◽  
Fixed Temperature ◽  
Wax Pattern ◽  
Shell Mould

One of the research directions of this study is to determine the possibility of making precise, thin-walled castings from selected iron alloys. The scope of research work is aimed at determining the applicability of the casting process of selected iron alloys with the technology of wax pattern, for making precise castings with a wall thickness of less than 3 mm. The article presents the results of tests carried out for experimental castings with the shape of steps, characterized by different wall thicknesses: 1 mm, 5 mm, 10 mm, 25 mm. The castings were made of LH14, Gs42crMo4, L35H7MP2, LH26N9, 316L cast steel, and a new alloy marked “0”. The metal was smelted in an induction furnace with a capacity of 150 kg. The technology of ceramic shell mould used in the plant was used to make the experimental castings. Ceramic shell moulds were heated in a chamber furnace at a fixed temperature. The time of annealing the ceramic mould was constant in a ceramic form. The following parameters were variable during the tests: iron alloy, pouring temperature, and annealing temperature of the ceramic shell mould.

scholarly journals The Impact of the Thickness of the Ceramic Shell Mould on the (γ + γ′) Eutectic in the IN713C Superalloy Airfoil Blade Casting

2017 ◽  
Vol 62 (2) ◽  
pp. 587-593 ◽  
Author(s):  
A. Szczotok ◽  
J. Nawrocki ◽  
J. Pietraszek
Keyword(s):  
Wall Thickness ◽  
Cross Sections ◽  
Volume Fraction ◽  
Suction Side ◽  
Chemical Compositions ◽  
Ceramic Shell ◽  
Wax Pattern ◽  
Shell Mould ◽  
Blade Casting ◽  
The Impact

AbstractIn the study the wall thickness of ceramic shell mould influence on (γ+γ′) eutectic in the IN713C nickel-based superalloy airfoil blade casting was described.Two castings formed as a blade from two wax pattern assemblies were analysed. In the experiment in one pattern the thick ceramic layer was obtained on pressure side and in another one on suction side of the airfoil blade. The microstructure of the cross-sections of the castings were observed on polished and etched metallographic specimens. The microstructure and phases chemical compositions of specimens was analyzed by using the scanning electron microscope Hitachi S-4200 equipped with EDS. It was established, that wall thickness of ceramic shell mould affect size, shape and volume fraction of (γ+γ′) eutectic islands in airfoil blade made from IN713C superalloy.The analysis was provided in accordance to the typical statistical methodology [1].

The Bootstrap Analysis of One-Way ANOVA Stability in the Case of the Ceramic Shell Mould of Airfoil Blade Casting

2015 ◽  
Vol 235 ◽  
pp. 24-30 ◽  
Author(s):  
Agnieszka Szczotok ◽  
Jacek Nawrocki ◽  
Aneta Gądek-Moszczak ◽  
Maciej Kołomycki
Keyword(s):  
P Value ◽  
Bootstrap Analysis ◽  
Wax Pattern ◽  
Bootstrap Approach ◽  
Shell Mould ◽  
Single Number ◽  
Blade Casting ◽  
The Impact ◽  
One Way Anova ◽  
F Statistics

The analysis of variance (ANOVA) is a classic tool for an identification of discreet factors impact on the measurable output by a specific decomposition on a total variance according to the scheme proposed by R.A Fisher in the 1920s. There are many explicit and implicit assumptions required as a preliminary of ANOVA computations. The ANOVA computations scheme is well known and implemented in many types of software but all estimations are provided with the assumption of a normal and homoscedasticity distribution of the noise disturbing the output. Computation procedures produce a single number output (e.g. F statistics, p-Value) without any analysis of their own dispersion. This paper analyzes the ANOVA output using the bootstrap approach. It seems to be the most convenient as a data-driven procedure. The source raw data are taken from the image analysis conducted during the investigation of the impact of the ceramic layer thickness on the wax pattern assembly of a turbine blade on the (γ+γ’) eutectic in the IN713C superalloy.

Numerical Simulation of Casting Deformation and Stress of A356 Aluminum Alloy Thin-Walled Frame Casting

2021 ◽  
Vol 1033 ◽  
pp. 24-30
Author(s):  
Yi Dan Zeng ◽  
Li Tong He ◽  
Jin Zhang
Keyword(s):  
Aluminum Alloy ◽  
Casting Process ◽  
Mold Temperature ◽  
Hot Cracking ◽  
Thin Wall ◽  
A356 Aluminum Alloy ◽  
Pouring Temperature ◽  
Thin Walled ◽  
Alloy Castings ◽  
A356 Aluminum

One of the main reasons for the scrap of cast thin-wall frame aluminum alloy castings is deformation and cracking. It is an effective method for solving the problem by predicting the distribution of casting stress, clarifying the size of the deformation and the location of the crack, and taking necessary measures in the process. This paper uses the ProCAST software to simulate the thermal stress coupling of A356 thin-walled frame castings, analyzes the influence of pouring temperature, pouring speed and mold temperature on the stress field distribution of castings, predicts the hot cracking trend and deformation, and optimizes Casting process..

The Effect of Intermetallic Phases on Ductile to Brittle Transition of Aluminium-Iron Alloy

2014 ◽  
Vol 592-594 ◽  
pp. 770-775
Author(s):  
Shahrukh Shamim ◽  
Gaurav Sharma ◽  
Chandrabalan Sasikumar
Keyword(s):  
Fracture Toughness ◽  
Grain Size ◽  
Transition Temperature ◽  
Research Work ◽  
Iron Alloy ◽  
Energy Transition ◽  
Intermetallic Phases ◽  
Impact Testing ◽  
Brittle Transition ◽  
Ductile To Brittle Transition

The effect of intermetallic phases and grain size on ductile to brittle transition temperature of Aluminium-Iron alloy (Al–11% Fe) was investigated in this research work. An Izod impact testing method was adopted to study the DBTT in the temperature interval of 77 K to 373 K. The ductile-brittle transition points: fracture transition plastic (FTP), fracture-appearance transition temperature (FATT), impact energy transition temperature (IETT), fractional surface area of cleavage (brittle) and fibrous (ductile) fractures and grain size of the samples were also determined. The fracture toughness of Al-Fe alloy found decreasing with temperature in contrast to conventional materials. The fractographic investigation revealed that the microstructural changes play a major role in determining the fracture toughness of these alloys. Annealing of these samples slightly improved the fracture toughness as the spherical morphology of intermetallic particles resists the crack propagation.

scholarly journals Spontaneous generation of heat in recently hardened steel

1917 ◽  
Vol 93 (649) ◽  
pp. 188-211 ◽  
Keyword(s):  
High Temperature ◽  
Tool Steel ◽  
Royal Society ◽  
High Speed ◽  
Research Work ◽  
Iron Alloys ◽  
Chromium Steel ◽  
Hardened Steel ◽  
Spontaneous Generation ◽  
Measurable Quantity

The object of this paper is to show that various kinds of steel, including carbon tool steel, “high speed” tungsten-chromium steel, and other similar iron alloys, after being quenched at a high temperature and hardened, spontaneously generate heat for at least several weeks in appreciable and measurable quantity, the rate of generation of course steadily diminishing. The paper is divided into two sections. First the research work relating to this discovery which originated with one of us (Brush) and which in the second part has been further experimented upon and verified by one of us (Hadfield). As the paper contains important new facts of much interest, it seems desirable that the results should be brought before the Royal Society.

scholarly journals Surface Modification of Cored, Thin Walled Castings of Nickel Superalloy IN-713C

2015 ◽  
Vol 15 (3) ◽  
pp. 17-20
Author(s):  
F. Binczyk ◽  
J. Cwajna ◽  
P. Gradoń ◽  
M. Mańka ◽  
R. Findziński
Keyword(s):  
Internal Surface ◽  
Nickel Superalloy ◽  
Pouring Temperature ◽  
Fine Grained ◽  
The Core ◽  
Modification Process ◽  
Mould Surface ◽  
Wax Pattern ◽  
Fine Grained Structure ◽  
Thin Walled

Abstract In current casting technology of cored, thin walled castings, the modifying coating is applied on the surface of wax pattern and, after the removal of the wax, is transferred to inner mould surface. This way the modification leading to grain refinement occur on the surface of the casting. In thin walled castings the modification effect can also be seen on the other (external) side of the casting. Proper reproduction of details in thin walled castings require high pouring temperature which intensify the chemical reactions on the mould – molten metal interface. This may lead to degradation of the surface of the castings. The core modification process is thought to circumvent this problem. The modifying coating is applied to the surface of the core. The degradation of internal surface of the casting is less relevant. The most important factor in this technology is “trough” modification – obtaining fine grained structure on the surface opposite to the surface reproduced by the core.

scholarly journals Experimental investigations on Thermal Performance of Copper with Aluminium Based Finned Heat sinks for Electronics Cooling System

2016 ◽  
Vol 12 (12) ◽  
pp. 4582-4587
Author(s):  
Arulmurugan Loganathan ◽  
Ilangkumaran Mani
Keyword(s):  
Thermal Performance ◽  
Heat Sink ◽  
Cooling System ◽  
Research Work ◽  
Electronics Cooling ◽  
Heat Sinks ◽  
Major Constituent ◽  
Experimental Investigations ◽  
Pure Aluminium ◽  
Fixed Temperature

An Experimental investigation on the thermal performance of copper with aluminium based finned heat sinks for electronics cooling system was studied. The heat sinks have different material proportions containing major constituent of aluminium and minor constituent of copper. Considered with straight finned heat sink for the experiments for its easiness in fabrication and efficient heat transfer properties. The observational results for aluminium with copper alloy are compared with pure aluminium heat sink.  Heat sink geometry, fin pitch and its height were taken from the commercially available heat sinks. In this research work best heat sink geometry is chosen and cooked up with different volume of copper added with aluminium. Selected four different spots of heat sinks and the temperature raising characteristics were measured for natural convection. also the temperature is raised to a fixed temperature and the temperature lowering characteristics were measured in forced convection as the air circulation takes more heat to keep the heat sink temperature within the desired level.

Toughening of Ceramic Shell Mould with Rice Husk Fiber (CSm-RH) to Improve Strength Property and Mould Performance

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Noor Hasliza Kamarudin ◽  
◽  
Zawati Harun ◽  
Rosniza Hussain ◽  
Mohd Riduan Jamalludin ◽  
...  
Keyword(s):  
Rice Husk ◽  
Investment Casting ◽  
Ceramic Body ◽  
Ceramic Shell ◽  
Adhesion Properties ◽  
Ceramic Structure ◽  
Green Strength ◽  
Body Strength ◽  
Shell Mould ◽  
Casting Industry

For ages, ceramic shell mould (CSm) have been extensively applied in investment casting industry. The formation of CSm requires multiple steps of dipping, layering drying and firing stages. The later steps are very crucial as the solidification thin layer CSm that consist of loose ceramic particles easily cracks when exposed to the higher thermal effect. The inclusion of fiber or any reinforces phases is able to enhance fired ceramic body and also strengthen the green ceramic structure. Thus, the feasibility of rougher NaOH treated rice husk fiber (RHT) prior embedded into composited structure has shown a significant CSm improvement by induced a better adhesion properties and larger bonding area with brittle ceramic matrix, resulted in increased green strength (1.34 MPa) and fired body strength (4.32 MPa). Owing to the decomposed of lignin layer in CSm with untreated rice husk fiber (CSm-RHU) exhibited a higher porosity that provide a better permeation paths of air flow during molten metal pouring as increased 30 % from the standard CSm permeability, giving an enormous benefit for investment casting cooling process. Overall, the incorporation of RHT fiber in a CSm matrix of both green and fired body governed in toughening of brittle ceramic body, hence avoid failure to the casting mould.

Refinement of Primary Silicon Grains in Semi-Solid Al-25%Si Hypereutectic Aluminum Alloy Slurry

2019 ◽  
Vol 285 ◽  
pp. 153-160 ◽  
Author(s):  
Wei Min Mao ◽  
Peng Yu Yan ◽  
Z.K. Zheng
Keyword(s):  
Grain Size ◽  
Aluminum Alloy ◽  
Research Work ◽  
Good Method ◽  
Primary Silicon ◽  
Pouring Temperature ◽  
Channel Bend ◽  
Traditional Process ◽  
Semi Solid ◽  
Inner Channel

s: The semi-solid slurry of Al-25%Si hypereutectic aluminum alloy was prepared through a copper serpentine pouring channel, the effect of pouring temperature and numbers of channel bend on the slurry microstructure was investigated. The results show that the primary silicon grains in Al-25%Si hypereutectic alloy solidified at a traditional condition are very large and the average silicon grain size is about 65.3μm, however, when the liquid Al-25%Si alloy is poured through a copper serpentine pouring channel, the primary silicon grains are fined obviously. If the channel has three bends and the pouring temperature is 747°C,the average silicon grain size in the slurry is about 33.7μm. If the channel has four bends and the pouring temperature is 747°C, the average silicon grain size in the slurry is about 30.9μm. If the channel has seven bends and the pouring temperature is 747°C, the average silicon grain size in the slurry is about 28.6μm. The analysis shows that the chilling effect of the inner channel wall precipitates primary silicon nuclei, and so the primary silicon grains of Al-25%Si alloy are fined greatly. Meanwhile, the subsequent washing of the alloy melt also promotes the separation of primary silicon grains from the inner wall and the primary silicon grains are further fined. The above research work demonstrates eventually that the copper serpentine pouring channel process is a good method for fining the primary silicon grains in hypereutectic Al-25%Si alloy rather than using chemical fining agent phosphorus as in traditional process.

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